Stacking machine



June 30, 1959 Filed Sept. 4, 1956 F. E. SIMPSON 2,892,631

STACKING MACHINE 8 Sheets-Sheet 1 INVENTOR FRANK E. SIMPSON ATTORNEY June 30, 1959 F. E. SIMPSON 2,892,631

smcxme MACHINE Filed Sept. 4, 1956 s Sheets-Sheet 2 INVENTOR FRANK E. SIMPSON ATTORNEY gum W59 F. E. SIMPSON 2989295331 STACKING MACHINE Filed Sept'. 4. 1956 s Shets-Sheet 5 INVENTOR FRANK E. SIMPSON Mia WW- ATTORNEY STACKING MACHINE Filed Sept. 4, 1956 8 SheetsSheet 4 F'lI3 1 mvsm'on FRANK E. SIMPSON BYW T W ATTORNEY 8 Sheets-Sheet 5 Filed Sept. 4, 1956 ll v i l FRANK E. SIMPSON ATTORNEY 8 Sheets-Sheet 6 Filed Sept. 4, 1956 INVENTOR FRANK E. SIMPSON M m & wv w ATTO RNEY' June 30, 1959 F. E. SIMPSON STACKING MACHINE 8 Sheets-Sheet 7 Filed Sept. 4, 1956 TIE EI '62 FRANK E. SIMPSON BY Mm Am wfl- ATTO RN EY STACKING MACHINE Filed Sept. 4, 1956 8 sheet s Sheet s INVENTOR l 4/ H4 FRANK E. SIMPSON ATTORNEY Unite-d 51 M P tent f STACKING MACHINE Applieation September 4, 1956, Serial No. 607,828

s can... (Cl. 271-87) This invention pertains to apparatus for handling sheet material, and more particularly, to amachine for receiving a succession of bags or sheets and arranging them in an orderly group or stack.

Oneobjectof the present invention is to provide a noveliandefiicient machine for stacking bags made of sheet material such as cellophane or thelike. Another object of the present invention is to provide an improved mechanism adapted to receive bags presented to it successively ,and to arrange them in stacked relation. 3 l Anot.her object is toprovide a mechanism for stacking 'sheetmatejrial articles presented successively thereto and for arranging them in groups eachof which contains a predetermined number of the articles. r

Another object is to provide a stacking machine adaptedto'jhandle" sheetmaterialarticles in a wide variety of sizes without'requiring adjustment. T

These and other objects and "advantages of the invention will become apparent from the following description and the accompanying drawings, wherein: ig. 1 is a side elevation ofthe stacking device of the present invention. s

Fig. 2,is,a rear elevation of the device shown in Fig. 1.

Fig. 3 is a section taken along line 3-3 of Fig. 1.

Fig. 4 is a section taken along line 44 of Fig. 2.

Fig. 5 is an enlarged fragmentary section taken along line 4-4 of Fig. 2. f r

Figs'. ,6, 7 and 8 are. fragmentary sections similar to Fig. 5 illustrating successive stages of the transference of a bag from ajbag" making machine to thestacking machine of. the invention.

.Fig. 9 isia fragmentary section illustrating thefmechanism for: releasing the bags or sheets at the stacking station.

Figl 10.is a fragmentary perspectiveiof one of the gripping 'unitsof the stackingmachineof the invention.

' Fig. 11 is an end elevation of the gripping unit shown in Fig. 10. i

Fig. 12 is a section taken along line 12-12 of Fig. 11.

For the purposes of illustration, the stacking machine of the present invention is disclosed in connection with a bag making machine of the type shown in the United States patent application Serial No. 310,637, filed September 20, 1952, by Harry A. Mead, entitled Automatic Bag Making Machine}? now Patent No. 2,762,271, issued September 11, 1956, and reference is made to said patent for the details of the bag making machine. It should be noted, however, that'the stacking machine of the present inventionis adaptable for use with other types of bag making machines, or,'in fact, with any type of machine whichlisadapted to feed bags or sheets successively to the stacking machine.

As shown inFig. 4; the bag making machine comprises arconveyor A (corresponding to the conveyor 14 of said Patent No. 2,762,271), which carries tubular bag blanks from a cutting mechanism (not shown) to heat sealing units'B on a rotatable drum C (corresponding 2,892,631 Patented-lune 30,

to the heat sealing units 42 on the drum 21- of said Patent No. 2,762,271), whereby the bottoms of the bags are sealed as the drum rotates through approximately 180?. After the bottoms of the bags have been heat sealed by the units B, the bags are presented to the stacking ma{ chine of the invention, which includes gripping units D on a stacking conveyor E and whereby the bags are car: ried to a stacking station F at which point the gripping units D are opened to release the. bags in a manner caus ing them to be aligned in an orderly stack. 7

The heat sealing units B and the drum C are construct: ed in the manner fully described in said Patent No. 2,762,271. Therefore, it will, sufiice for the purposes of the present disclosure to explain that each of the heat'seal units. B'comprises an electrically heated bar 20 (Figs.

4-8) mounted on the drum C in parallel relation to the axis'thereof, and a clamp 22 fixed to a shaft 24 rotatably mounted on the drum C in position adjacent and parallel to the bar 20. A cam follower 26 is operatively connected by an arm 27 (Fig. 3) to the shaft 24 and cooperates with a cam groove 28 in a plate cam 29 adjacent one end of the drum to pivot the clamp 22 toward and away from the bar 20 at the appropriate times. A tucking plate 30 (Figs. 48) is fixed to the drum C. parallel to" and adjacent the rearmost portion of the bar 20, when considered with respect to the direction of rotation of the drum C, and projects radially outward from said drum. .The drum C is provided with two stub shafts 32 and 34, one fixed to each end of the drum and projecting outwardly'therefrom (Figs, 2 and 3). The stub shafts 32 and 34 are rotatably mounted in bearings 33 and 35 fixed to side frame members 36 and 38, respectively.

' As best seen in Figs. 3 and 4, a second drum 40 is mounted above the drum C. The drum 40 is provided with two outwardly projecting hubs 42 and 44 rotatably supported in two bearings 46 and 48 mounted on the side frame'members 36 and 38, respectively.

The stacking conveyor E comprises a pair of endless chains 50 and 52 (Figs. 2 and 3), and a plurality of cross bars 54 (Figs. 2', 3 and 4) extending therebetween. The chain 50 is trained around a drive sprocket 56'fixed to the hub '42 of the drum 40 and around three idler sprockets '58, 60and 62 in the manner'shown in Fig. 4. Similarly, the chain 52 is trained around a drive sprocket 64 (Fig. 3) fixed to the hub 44 of the drum 40 and idler sprockets 66, 68 (Fig. 2) and 69 (Fig. 3). The idler sprockets 58 and 66 are mounted on a shaft 70 extending transversely between and rotatably mounted in two sideplates 71 and 72 fixed to the side frame mem bers 36 and 38, by pairs of brackets 73 (Fig. 2) and 74 (Fig. 1), respectively. Similarly, the sprockets 60 and 68 are fixed to a shaft 79 extending transversely between the plates 71 and 72 and supported by two plates 83 and 85 (Figs.'l and 2) adjustably secured to the plates 71 and 72, respectively. The plates 83 and 85 are mov able vertically'to adjust the slack in the conveyor belt E. The sprockets 62 and 69 are fixed to a shaft 80 extending transversely betweenand rotatably mounted in the side plates 71 and 72. I

The links of the chain 50 are each formed with an integral,inwardlyrprojecting tab (Fig. 3). Similarly, the links of the chain 52 are each formed with an integral inwardly projecting tab 76. Each opposed pair of tabs 75 and 76carries one of the bars 54 which is fas= tened thereto by machine screws 77 and 78.

The drum 40 and the drive sprockets 56 and 64 connected thereto are driven in timed relation with the drum 86 rotatably mounted on the frame 87 of the "bag making machine. A sprocket -88 fixed to the shaft 86 is driven by a chain in proper timed relation with the bag making machine, for example, in the manner fully described in said Patent No. 2,762,271. a a v H v The gripping u "ts D are four in nunrbeg and h Y 31 equally spaced along the length of the stacking conveyor E in the manner shown in Fig. 4, the space' between units being equal to one half the circumference of the drum C, All' of the gripping units D are alike in construction and in their mounting to each of the chains 50 and 52 Therefore, only one unit and the mounting thereof at but one end will he described in detail. The main bar of a gripping unit D is cut out at its end toforrn a recess. 102 (Fig. 12) and a link-shaped block 104 positioned within the recess 102, is fastened to the bar 10 by a screw 106. The pins 108 and 110 that pivotally intercorinectlinksof the chain 52 are elongated and extend into the block 104 to mount the bar 100 to the chain 52. The parlor is generally rectangular in shape with the outer, forward edge chamfered as indicated at 112 and with a ra'r'wa'rdly projecting shoulder 114 at its outer rear corner. l;- shaped block 116 is fastened to the bar 100 by a' screw 118 and extends upwardly therefrom. A cylindricaljend po'r tion 122 of a square bar projects through a suitable aperture in the block 116 to rotatably mountthe' bar 120 on the block 116-. A collar 124 is fixed to the projecting end of the cylindrical end portion 122 of the bar 120 by a set screw 126. A torsion spring 128 surroundsjthe cylindrical end portion 122 of the bar 120 between theicolla'r 1 24 and the block 116. One end of the spring 128 is fixed to the collar 124 and the othererrdtoblock 116. A clamping plate 130 is fixed to the bar 120 by a plate 132' and a plurality of screws 134 extending' through suitable apertures in the plate 132 and slots'1'36 in the up er edge of the clamping plate 130 and threaded into the bar 120. The torsion spring 128 tends to rotate the bar 120 in a clockwise direction as viewed in Fig. 11 to urge the lower portion of the clamping plate 130 toward the rearwardly projecting shoulder- 11-4 on the pardon. I I An arm 1'40 is'fixed to the bar .120 by a s rew 142 and extends forwardly therefrom. I The arm carries at its forward end astub shaft 144' on which a cam follower roller 146 is rotatably mounted. The roller 146 is adapted to ride on the cam surface of a cam 148 and be actuated thereby to rotate the bar 120 in a manner to move the clamping plate 139 away from the shoulder 114 against the" action of the torsion spring 128'. v Two-cams 148' are provided Within the space enclosed by the conveyor E, for actuating the rollers 146, one roller 146 being associated with each end'of each bar 120. Theca'ms148 operate to open the gripping units D to permit engagement of the bags thereby. T e 148 are mounted on a shaft 150' (Fig 3'), which projects outwarftily through the hubs 42 and 44 of the'dru'm 40 andji's supported for" rotationall adjustment in suitable sockets provided in the caps 152, and 154 of the bearings 46 and 48, respectively. An adjusting arm 156 is fixed to each end of the shaft 150 and is engaged between two opposed timing set screws 158, only one of which is shown (Fig.

A second pair of cams 160, only one ofwhich is shown (Figs. 4 and 9'), are arranged within the space enclosed by the conveyor E to open the gripping units to; release the bags at the stacking station F. The cams: l60 surround the shaft 79, a bearing 159 being interposed be tween the shaft 79 and each cam-1 60 to permit the shaft to rotate while the cams remain motionless, Each cam 160 isrigidly secured to the associated adjusting pl t 3 3 9 i ss ss m h b by a-p .1 1;-

A pair of angle brackets-162 and 164 (Figs. 2 and 4) are attached to the, plates 71 and 72; respectively,- adjacent the-1ower rear corners thereof, and a horizontalnstacking shelf 166issupportedon the bra'ckets1162 and 164;, The shelf- 166 is providedwith a central; longitudinally ex tending groove 168' in its upper surface.- A backing unit 7 4 170 (Fig. 4) rests on the shelf 166 with a downwardly projecting flange 172 thereof received in the groove 168. The backing unit 170 is provided with a vertical plate 174 adapted to abut the outermost bag in a stack being formed on the shelf 166 and support all the bags comprising the stack in an upright position.

All of the conveyor bars 54, the gripper bars 100 and the gripping plates 130 are provided with a plurality of transversely spaced, longitudinally aligned slots extending in the direction of movement of the stacking conveyor E (Figs 2, 3 and 10). Aplu'rality of stripping belts are adapted to lie in said slots and travel with the conveye v Asthe conveyor E bends around the sprockets 60 and 68' adjacent the stacking station F, and the gripper units D are released' hy the cams 160, the stripper belts 180 continue in a straight line, thus separating from the conyevor E to strip the bags therefrom. The stripperbelts 180 then bend around a grooved pulley rsz rotatably mounted on a shaft 184 (Figs. 21186.4) ex: tending between the pl'ates 71 3, d72 below thelevel of the stacking shelf 166. The belts 180 then trayelovetf another grooved pulley 186 (Fig, 4) rotatablym'ounted on the hereinbefore mentionedshaft 80, and again seat in the slots in the conveyor E as the ,conveyo'r E py proaches the drive sprockets 56 and 64. The stacking s'helf'166 is provided with, a forwardly projec'tingplate 188 (Fig'. 4)]having a plurality of suitable apertures through which the belts 180 pass. v, An automatic countin mechanism 189 is provided to divide the bagsb'ejrig stacked into groups each containing a predetermined number of bags. This counting mechanism comprises a bevel gear 190 (Fig. 1) fixed, to the previously described shaft 79 and meshing with a companion bevel garf192 fixed to a shaft 194 journalled on the plate" 85. A worm 196 on the shaft 194 meshes witha worm gear 198. vA cam 200 fixed to the gear 198 is adaptedto actuate an arm 202, which is pivotally mounted at 203 to the plate 85, to actuate a microswitch 204.

The microswitch 204 is interposed in .the electrical circuit (not shown) of a solenoid 206 (Fig. 2') fixed tothe plate 72.' The plunger 208 of the solenoid 206 is connected to a yoke 210 slidably mounted on two guide rods 212 and 214. A plate 216 connects the outer ends, of the rods 212 and 214 and limits the outward movement of the yoke 210. The ends of the yoke 210 are split and provided with apertures to slidably receive two rods 2 2 0 and 222. 7 Two transversely extending studs 224 and 226, respectively, are provided to squeeze the split ends and thereby clamp the yoke 210 to said rods. The rods 220' and 222 extend through suitable apertures in the plate 72 and carry on their inner ends an angle member 228. A pair of coil springs 230 and 232 surround the rods 220' and 222, respectively, between the yoke 210V and the plate 72 and normally urge the plate 228, toward the left as viewed in Fig; 2'. p k p The pitch diameters of the sprockets 60 and 68 are one half the pitch diameters of the drive sprockets 56 and 64. Hence the shaft 79 rotates at t-wice the speed of the drum 40, making one revolution for each bag delivered tothe stacking station E, The worm 196 and the worm gear 198 are so proportioned that the shaft 79 makes a predetermined number of revolutions for each revolution of the gear 198. 8 Each time the gear 198- makes a co mplete revolution, the microswitch204 is actuated to momentarily energize the solenoid 206 to move the angle member 228 to the rightas viewed in Fig. 2; and theedge thereof pushes one or more bags out of line withthe remaining bags stacked on the shelf-1'66, thus dividing the accumulating stack into groups each con taining a predetermined number of bags.

In the operation of the device, the leading edge of a bag G clampedlby a heat seal unit 3 approaches the top of the drum C as illustrated in Fig. 6. The bag G is drapedover the tucking plate 30 in the manner shown".

The gripper assembly D' on the stacking conveyor E is simultaneously approaching the bottom of the drum 40. As the gripping assembly D approaches the heat seal unit B it is opened by the cams 148. In Fig. 7 the elements are illustrated as having progressed until the heat seal unit B and the gripping unit D are in register with each other. In this position the tucking plate 30 is thrusting a fold or tuck 234 between the projecting shoulder 114 on the bar 100 and the clamping plate 130 of the gripping unit. The roller 146 is leaving the cam 148 and the plate 130 is being urged toward the shoulder 114 by the torsion springs 128 (Figs. 10 and 12) to grip the tuck 234. The shaft 24 of the heat seal unit B has been rotated slightly by the action of the cam groove 28 to release the bag from thet heat seal clamp 22.

As the elements move to the positions illustrated in Fig. 8, the tucking plate 30 is withdrawn from between the shoulder 114 and the plate 130 of the gripping unit D leaving the tuck 234 of the bag securely clamped therebetween. Accordingly, as the conveyor E advances, the bag is carried by the gripping unit D until it reaches the stacking station F at which point (Fig. 9) the cam 160 opens the gripping unit, causing the same to release the tuck 234. The bag is then carried downwardly into contact with the stacking shelf 166 by frictional contact with the bars 54 of the stacking conveyor F, and the stripper belts 180 peel the bag off the bars 54 so that the bars can follow their arcuate path about the shaft 79 without carrying the bag with them. In this manner, the bag is deposited onto the stacking shelf 166 in a vertical plane between the backing unit 170 and the conveyor E.

Since the leading edge of each gripping unit is chamfered as indicated at 112, it presents an inclined surface to the uppermost edge of a bag previously delivered to the stacking shelf, in the event that said uppermost edge tends to block entry of the next succeeding bag into position between the conveyor E and the previously stacked bags. Hence, the next succeeding bag approaching the stacking station F can pass between the preceding bag and the conveyor E without mussing or otherwise damaging either bag.

As succeeding bags are thus delivered to the stacking station F, they accumulate in an orderly stack behind the backing unit 170, which is pushed away from the conveyor E by the bags as the number of bags in the stack increases. When the apparatus has handled a number of bags corresponding to the tnumber of times the shaft 79 turns for each full revolution of the worm wheel 198, the automatic counting mechanism 189 will be actuated as hereinbefore described, causing at least one bag to be laterally ofiset in the accumulated stack, thus facilitating removal from the stack of any desired number of bags.

In view of the fact that the plate 130 and the shoulder 114 which constitute the opposed jaws of a gripping unit D extend throughout approximately the entire width of the conveyor E, the stacking machine of the invention is capable of handling bags of a wide variety of widths without requiring adjustment of any of its parts because the wide jaws 114 and 130 can handle either wide or narrow bags with equal efficiency. Since each bag is deposited onto the stacking shelf 166 with the full length of the bag in a vertical position, corresponding to the position that it will occupy within the stack, the stacking machine of the invention is adapted to handle bags of any length up to and including the distance between gripping units D of the conveyor E.

While a preferred embodiment of the present invention is desribed herein, it should be noted that various changes may be made therein without departing from the spirit of the invention as defined in the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

l. A stacking mechanism comprising a movable conveyor made up of two parallel endless chains having their opposing links interconnected by a'plurality of cross bars in side-by-side relation with each other, means for moving the conveyor, a plurality of spaced apart gripping units on said conveyor, means for feeding bags to said conveyor in timed relation with the movement theerof, means adjacent said conveyor for actuating said gripping units to receive and grip said bags, guide means for said conveyor causing one portion of its travel to be vertically downward for a distance as great as the length of one of said bags, means adjacent the lower end of said vertical portion of the path to actuate said gripping units to release the bags, a stacking shelf adapted to receive the bags when released from said gripping units, said cross bars having therein a plurality of notches defining grooves in said conveyor extending longitudinally thereof, and a plurality of stripping belts received in said grooves and traveling with said conveyor but separable therefrom at the lower end of said vertical portion of the path to strip the bags from said conveyor.

2. A stacking mechanism comprising a movable conveyor made up of two parallel endless chains having their opposing links interconnected by a plurality of cross bars in side-by-side relation with each other, means for moving the conveyor, a plurality of gripping units on said conveyor at spaced intervals therealong, each of said gripping units including a first bar fixed to the chains of said conveyor, a second bar mounted parallel to said first bar and rotatable about its own axis, a plate fixed to said second bar and movable toward and away from said first bar by rotation of said second bar, spring means urging said plate toward said first bar, a cam follower arm fixed to said second bar, a cam follower on said arm, means for feeding bags to said conveyor in timed relation with the movement thereof, first cam means mounted adjacent said conveyor in position to be engaged by said cam follower to actuate said gripping units to receive and grip the bags, guide means for said conveyor causing one portion of its path to be vertically downward for a distance as great as the length of one of said bags, second carn means mounted adjacent the lower end of said vertical path in position to be engaged by the cam follower to actuate said gripping units to release the bags, a stacking shelf adapted to receive the bags when released from said gripping units, and stripping belts traveling with said conveyor but separable therefrom at the lower end of said downward path to strip the bags from said conveyor.

3. A stacking mechanism comprising an endless conveyor made up of two parallel endless chains having their opposing links interconnected by a plurality of cross bars in side-by-side relation with each other, a plurality of gripping units on said conveyor spaced at equal distances thcrealong, each of said gripping units including a first bar fixed to the chains of said conveyor, a second bar mounted parallel to said first bar and rotatable about its own axis, a plate fixed to said second bar and movable toward and away from said first bar by rotation of said second bar, spring means urging said plate toward said first bar, a cam follower arm fixed to said second bar, a cam follower on said arm, means for feeding bags to said conveyor in timed relation with the movement thereof, first cam means mounted adjacent said conveyor in position to be engaged by said cam follower to actuate said gripping units to receive and grip the bags, guide means for said conveyor causing one portion of its path to be vertically downward for a distance as great as the length of one of said bags, second cam means mounted adjacent the lower end of said vertical path in position to be engaged by said cam follower to actuate said gripping units to release the bags, a stacking shelf adapted to receive the bags when released from said gripping units, said cross bars having a plurality of notches therein defining grooves in said conveyor extending longitudinally thereof, and a plurality of stripping belts received in said grooves and traveling with said conveyor but s'eparabletherefrom at the lower end of said vertical path to stripzthe' bags from said conveyor.

, 4. Mechanism. for stacking bags of cellophane or like yieldable material, comprising a conveyor, means for moving saidconveyor in an endless path of travel, said means including a plurality of sprockets over which said conveyor is trained, said conveyor having a downwardly moving vertical portion defined by and extending between the horizontal planes of the axes of a pair of said sprockets disposed in vertically spaced relation, a plurality of grippers on said conveyor at spaced intervals therealong, means for feeding bags to said conveyor in timed relation with the movement thereof, means adjacent said conveyor, for actuating. said gripping. units to receive and grip the bags, cam r'n'eans adjacent the lower end of said vertical conveyor portion for actuating said gripper units to release the bags wit'h the major length thereof directly engaging said vertical conveyor portion; and a stacking shelf disposed beneath the lower end of said downwardly moving vertical conveyor portion for receivingv and stacking the-released bags. V

5. Mechanism for stacking bags of cellophane or like yieldable material; comprising. a conveyor, means for moving saidsconveyor in an endless path of travel, said means including a plurality oisprocltets over which said conveyor is trained, said conveyor having a downwardly moving vertical portion defined-- by and extending Between the horizontal planes of the axes of. ayvpair of said sprockets disposed in' vertically spaced relation, aplurality of grippers on said conveyor at spaced intervals there along, means for feeding bagsto said conveyor in timed relation with the movement thereof, means. adjacent said conveyor for actuating said gripping units to receive and grip the bags, cam means adjacent the lower end of said vertical conveyor portionfor actuating said gripper units to release the bags with the major length thereof directly engaging said vertical conveyor portion, a stacking shelf disposed beneath the lower end of said downwardly nioving vertical conveyor portion for receiving and stacking the released bags, and stripping belts traveling with said conveyor and separahlegtherefrom at the lower end of said vertical portion thereof for stripping the bags from said conveyor;

inferences (lifted in the iil'e' of this patent UNITED: STATES" PATENTS 

